Solid state method for converting small pieces of metal into a void-free workpiece

ABSTRACT

A method of converting scrap or other small pieces of metal into a useful, commercial product while maintaining the metal in a solid state. According to the process, the pieces are maintained together for further processing. They are impacted, while heated, to produce a metal body and thereafter subjected to continued impaction so that the pieces forming the body are welded together into a cohesive, homogeneous slab. There is also disclosure of a novel press and method of operating the press. The press is of the harmonic type. Its novel aspects include control of movement of novel platens during rotation of shafts which drive the platens and perimetral constraint of a workpiece being forged to achieve rapid impaction and self feed of a workpiece. There is also disclosure of a novel method for making flakes of steel, a novel furnace including seals for maintaining the furnace gas-tight, a novel method in which the pieces of metal are scrap steel and baled together into a bale in which the scrap pieces of random size and shape become intertwined together and novel processes and apparatus for cleaning scrap or other metal pieces.

United States Patent [1 1 Whalen et al.

[11] 3,768,139 [451 Oct. 30, 1973 I SOLID STATE METHOD FOR CONVERTING SMALL PIECES OF METAL INTO A VOID-FREE WORKPIECE [75] Inventors: Mark E. Whalen, Pepper Pike; Norman W. Trepainier, Rocky River; Robert A. Kraus, Shaker Heights; Joseph W. Malleck, Chagrin Falls, all of Ohio [73] Assignee: Republic Steel Corporation,

Cleveland, Ohio [22] Filed: Mar. 8, 1971 [2]] App]. No.: 122,110

[52] U.S. Cl 29/403, 29/420, 29/420.5, 100/38, 264/111, 425/78 [51] Int. Cl B23q 17/00 [58] Field of Search 29/403, 420, 420.5; 425/78; l8/DlG. 46; 100/35, 38; 264/111 [56] References Cited UNITED STATES PATENTS 3,626,578 l2/l97l Price et al 29/403 3,115,676 12/1963 Quartullo.. 425/78 X 3,626,577 l2/l97l Trible 29/403 3,231,648 l/l966 Eyre et al. 264/1 ll 3,629,929 12/1971 Wessel 29/403 2,21 I984 8/1940 Paterson 29/403 2,l23,4l6 7/1938 Graham 29/420 99,574 2/l870 Jones 29/420 X 2,100,537 ll/l937 Conway 29/403 X Primary ExaminerCharIes W. Lanham Assistant Examiner-D. C. Reiley, Ill Attorney-Robert P. Wright [57] ABSTRACT A method of converting scrap or other small pieces of metal into a useful, commercial product while maintaining the metal in a solid state. According to the process, the pieces are maintained together for further processing. They are impacted, while'heated, to produce a metal body and thereafter subjected to continued impaction so that the pieces forming the body are welded together into a cohesive, homogeneous slab. There is also disclosure of a novel press and method of operating the press. The press is of the harmonic type. Its novel aspects include control of movement of novel platens during rotation of shafts which drive the platens and perimetral constraint of a workpiece being forged to achieve rapid impaction and self feed of a workpiece.

There is also disclosure of a novel method for making flakes of steel, a novel furnace including seals for maintaining the furnace gas-tight, a novel method in which the pieces of metal are scrap steel and baled together into a bale in which the scrap pieces of random size and shape become intertwined together and novel processes and apparatus for cleaning scrap or other metal pieces.

53 Claims, 34 Drawing Figures SELECTING PIECES OF STEEL POSITIONING MAINTAINING TOGE AND THEN THER THE PIECES HEATING T TO FROM I400 HE PIECES TO 2000 F.

IMPACTING THE PIECES WHILE HOT WITH A HIGH STRAIN RATE FORGING ACTION UNTIL A SOLID WORKPIECE IS FORMED.

minimum 30 I975 3. 768.11 39 sum 010F 21 SELECTING PIECES OF STEEL POSITIONING AND THEN MAINTAINING THE PIECES TOGETHER HEATING THE PIECES TO FROM I4OO TO 2000 F.

IMPACTING THE PIECES WHILE HOT WITH A HIGH STRAIN RATE FORGING ACTION UNTIL A SOLID WORKPIECE IS FORMED.

CONTINUING THE IMPACTION UNTIL THE WORKPIECE IS FURTHER REDUCED IN THICKNESS AND A COHESIVE HOMOGENEOUS SLAB IS FORMED.

INVENTORS. MARK E. HALEN NORMAN W. TREPANIER BY ROBERT A. KRAUS ATTORNEYS PATENTED BET 3 0 I975 v 3.768.139 SHEET 020E 21 INVENTORS. MARK E. WHALEN NORMAN W.TREPAN|ER BY ROBERT A. KRAUS ATTORNEYS PAIENIEnumao ms 3 758, 139

SHE CW 0F 21 I T g MARK E.WP i K E I J NORMAN W.T EPANIER BY ROBERT A.KRAUS I JOSEP w. MALL cu ATTORNEYS E T MARK E. WWXfiN NORMAN W. TREPANIER ATTORNEYS PATENTED OCT 3 0 I975 saw as 0F 21 A.KRAUS w. MALILECH gffimfg ATTORNEYS PAIENTEUIIBIBO I975 3.768.139 sum over 21 E 0R5. MAR E.WHL NOR AN WJ R P NIER BY ROBERA'AKRAUS ATTORNEYS PAIENTEnumaown 3.768.139

SHEET 080F 21 I EN RS. RK wry/K65 OSMAN W. TREPANIER ATTORNEYS PATENTEUnmso ms 3.768.139

sum 080F121 L j '2 M52 K 'INVENTORS ,g MARK E.WHALEN NORMAN W.TREPANIER BY ROBERT A. KRAUS ATTORNEYS PATENTEBDBIBO I975 3.768.139

NORMAN W.'TREPAN|ER BY 5? BERTAKRAUS E A w 2%; fiz 2322. 5

ATTORNEYS PAIENIEDBCT 30 I975 3.768.139

SHEET 12 0F 21 E 0R5 MARK E. WWXLEE N8RMAN w. TREPANIER R SBERTA KRAUS ATTORNEYS PATENTEBBBI 30 ms SHEET 130F 21 E ORS mssmmfimm BY 8E mesa ww my img ATTORNEYS PAIENTEU 0U 30 I973 SHEET 1 40! 21 WTREPANIER A. KRAU JOSEPH W. MALL BY 3 I ECH Wfl M 4 I ATTORNEYS INVENTORS. MARK E.WHALEN NORMAN W. TREPANIER BY ROBERT A.KRAUS ATTORNEYS PATENTEUUEISO I975 (17 1 3 SHEET IBUF 21 INVENTORS MARK E.W ALE NORMAN W TREP XNIER BY ROBERT A.K 6U

PATENTEUUIIISO I875 3,768,139

sum 17 0F 21 ATTORNEYS PATENTEDUCIIQO I973 11,788,139 SHEEI 18UF 21 254 Ill" INVENT R RK E. wHALEn? 5 RMAN.W.JR PANIER BERTA R EUS JOSEP W. m, mmfikrzfizzf ATTORNEYS 

1. The method of converting random sized small pieces of steel to a steel body suitable for use in a manufacturing operation while maintaining the steel in a solid state comprising: a. baling the randoM sized pieces and compacting the pieces until the bale is from 20 to 40 percent solid; b. thereafter compressing the bale by repetitively impacting the bale while the bale is perimetrally confined in planes of impaction until a time when the bale becomes substantially free of voids and then continuing to compress the bale until it is a slab having a transverse cross-sectional area reduced by at least 30 percent from the area at said time when the bale became substantially free of voids; and, c. heating said bale to from 1,200*F. to 2,350*F. prior to completion of step (b) while maintaining the steel in solid state.
 2. The method of claim 1 wherein the impaction is performed with a harmonic press.
 3. In method of claim 2 wherein the impaction is performed with a harmonic press having opposed platens and side restraints.
 4. The method of claim 1 wherein the impaction is performed with a pair of opposed, oppositely-acting platens impacting opposed outer surfaces of the bale while other outer surfaces of the bale are confined against lateral outward movement as the bale is impacted.
 5. The method of claim 3 wherein said bale is impacted with a platen achieving a velocity of at least four impacts per second whereby the sharpness of the impaction blow permits inertia of rest of the bale to contribute to the minimization of longitudinal dissipation of its impact forces.
 6. The method of claim 1 wherein metal powder is dispersed through the bale prior to completion of the compaction whereby to modify the chemistry of the finished product.
 7. The method of claim 1 wherein the compression is achieved by compaction with a platen and wherein side restraints are used to confine the sides of the bale and wherein during the compaction operation lips are formed by portions of the bale forced into interstices between the platen and the side restraints.
 8. The method of claim 7 wherein steel powder is deposited on the surface of the bale after said lips have been formed and between the lips and thereafter said bale is further compacted to provide a bale having a laminate of steel formed from said metal powder on a surface of the slab.
 9. The method of claim 8 wherein after said laminate is formed the bale is inverted, powder is applied to a surface of the bale opposite said laminate and said after-applied powder is impacted to form a second laminate of steel from the after-applied powder.
 10. The method of claim 1 wherein sheets of finished steel form sides of the bale whereby to provide smooth, finished surfaces on the bale formed from said sheets of steel after the bale has been compressed to a solid slab.
 11. The method of claim 1 wherein the temperature of the bale is raised to a temperature in excess of that required for welding the scrap steel together according to a pressure-temperature curve whereby grain growth on cooling of a finished slab is accelerated to assure full encompassment of any dirt particles on surfaces of the scrap.
 12. The method of converting selected metal pieces to a solid piece of metal usable in a manufacturing operation comprising: a. selecting pieces to provide a quantity of pieces of the desired chemistry of a finished body of material; b. bringing the temperature of the pieces to a temperature high enough to achieve a true pressure weld under conditions of confinement and pressure while maintaining the pieces in a solid state; c. feeding said quantity of pieces along a path through an impacting station and simultaneously repetitively impacting a surface of the quantity of pieces while constraining other surfaces against movement transverse of the path to minimize lateral dissipation of forces of impaction: d. said impacting being at a sufficiently great angular velocity to cause molecular migration among the pieces of metal while the inertia of rest of the pieces inhibits longitudinal dissipation of impaction forces and relative movement of pieces such thaT elongation occurs primarily only due to compaction of the pieces to a solid slab; and, e. thereafter continuing the impaction of the slab until the slab is a solid mass of united metal in which the surfaces of the original pieces have been welded to one another by molecular migration resulting from such impaction at said temperature.
 13. The method of claim 12 wherein the pieces are steel and the temperature is elevated to from 1,200*F. to 2,350*F. by heating in a furnace.
 14. The method of claim 12 wherein said pieces are of random and irregular size and shape and are mechanically interconnected in a baling operation.
 15. The method of claim 14 wherein the bale is placed in the first zone of a two-zone oven and while in the first zone elevated to from 1,000*F. to 1,200*F. in a neutral atmosphere and thereafter transported to the second zone wherein the temperature is elevated to from 1,200*F. to 2,350*F. in a reducing atmosphere.
 16. The method of converting scrap metal to a solid commercially usable product while maintaining the scrap metal in a solid state, comprising the steps of: a. selecting pieces of scrap metal having a chemistry substantially that of the desired finished chemistry of the product produced by the process; b. consolidating the selected pieces to form a consolidated mass; c. cleaning the pieces selectively either prior to or subsequent to the consolidation step but prior to impaction; d. heating the consoldiated mass prior to impaction to such a temperature as is required in combination with the pressures developed during impaction to effect welding by molecular migration while maintaining the metal in solid state; e. impacting the consolidated mass while hot by repeated impaction and while perimetrically confining the mass of pieces until the mass has been reduced to a slab of metal substantially free of voids and thereafter continuing to repeatedly impact the slab to further reduce its thickness.
 17. The method of claim 16 wherein the impaction is achieved by a pair of opposed platens and side restrainers are provided to prevent lateral displacement of the metal during the impaction.
 18. The method of claim 16 wherein the cleaning is accomplished by heating and tumbling the scrap in a kiln prior to the consolidation step.
 19. The process of claim 16, wherein the cleaning is accomplished after the consolidation step by immersing the consolidated mass in a cleaning solvent.
 20. The method of claim 19 wherein the cleaning solvent is perchloroethylene.
 21. The method of claim 19 wherein the consolidation step is accomplished at a location remote from a location where the impaction step is performed and wherein the consoldiated mass is oiled to inhibit oxidization during shipment from one location to another and the cleaning step is performed at the impaction location.
 22. The method of claim 16 wherein a plurality of consolidated masses are connected together prior to the impaction step whereby the finished slab is composed of scrap pieces provided by the plurality of connected consolidated masses.
 23. The method of claim 22 wherein the consolidated masses are connected by resistance welding.
 24. The method of claim 22 wherein the consolidated masses when formed have non-confined sides so that portions of the scrap project irregularly and wherein the consolidated masses are connected by bringing the irregular ends into contact and then compressing the consolidated masses together.
 25. The method of claim 22 wherein the consolidated masses are impacted to cause end portions thereof to open and thereafter at least one open end of each of the plurality of consolidated masses is brought into engagement with an open end of another of the plurality of the consolidated masses and the consolidated masses are thereafter compressed to interlock said engaging open ends.
 26. The method of claim 16 wherein when the cOnsolidated mass has been reduced to at least a substantially void-free condition, a layer of steel powder is deposited on a surface of the consolidated mass and another consolidated mass is superimposed above the layer of powder and thereafter the consolidated masses are further impacted to produce a slab having a layer of metal formed of said powder and layers of metal on either side of said powder layer formed from said consolidated masses.
 27. The method of claim 16 wherein said selected scrap pieces are tin cans and wherein said consolidated masses are heated to a temperature sufficiently high to vaporize a thin skin on said cans.
 28. The method of claim 16 including feeding the slab while still hot to a mill of the planetary type and thereafter rolling the slab to form plate.
 29. The method of claim 28 wherein the rolling is continued until the thickness of the plate is less than 1/20th of the thickness of the original consolidated mass.
 30. The method of claim 16, wherein metal powder is dispersed through the consolidated mass prior to the completion of the impaction whereby to modify the chemistry of the finished product.
 31. The method of claim 16 wherein metal powder is applied to a surface of the bale after it has been impacted to a solid condition and thereafter the bale is further impacted whereby to convert the steel powder to a thin layer of steel.
 32. The method of converting scrap steel to steel strip comprising the steps of: a. segregating scrap to select scrap pieces of steel having chemistry substantially that of the desired chemistry of a finished product; b. baling the segregated scrap pieces of steel in a baler to produce bales having a predetermined regular shape with at least 20% of the volume of said shape being comprised of steel scrap; c. cleaning said scrap prior to a subsequent compaction step either before or after said baling; d. compacting the bale while substantially at ambient temperatures by repeated impaction in a cold harmonic press until said bale is a shape having at least 30 percent of its volume composed of steel; e. heating said compressed bale in a two-zone oven to from 700*F to 1,000*F in the first zone in the presence of an oxidizing atmosphere and from 1,200*F to 2,350*F in the second zone in the presence of a reducing atmosphere while maintaining the steel in solid state; and, f. repeatedly impacting the bale while hot in a harmonic press of the type having a pair of opposed platens and side restraints until the bale is converted to a substantially void-free body of steel and thereafter continuing to repeatedly impact the body until it is reduced to a thickness of no more than 70 percent of its thickness at the time it became the substantially void-free body of steel whereby to convert the scrap to a slab of substantially homogenous steel.
 33. The method of claim 32 wherein said cleaning is accomplished in a rotary kiln.
 34. The method of claim 33 wherein said steel is heated to from 1,000*F. to 1,200*F. in said kiln in a reducing atmosphere.
 35. The method of claim 32 wherein said cleaning is accomplished by immersing the bale in a solvent.
 36. The method of claim 35 wherein said bales are oil treated to inhibit oxidization subsequent to the baling step but prior to the cleaning step.
 37. The method of claim 35 wherein the cleaning solvent is trichloroethylene.
 38. The method of claim 32 wherein said cleaning includes shot blasting.
 39. The method of claim 32 wherein the slab is transported while still hot to a rolling mill of the planetary type and the slab is rolled into plate having a thickness no more than 1/20th of the thickness of the original bales.
 40. The method of converting scrap steel to a steel workpiece comprising the steps of: a. segregating the scrap into selected scrap pieces having chemistry substantially that of the desired chemistry of A finished product; b. baling the segregated scrap pieces into a plurality of relatively small bales each having a predetermined regular shape at least 20 percent of the volume of the shape being comprised of steel scrap; c. shipping said bales to another location; d. connecting a plurality of bales to form a larger workpiece composed of said plurality of bales; e. heating said larger workpiece to a temperature of from 1, 200*F to 2,350*F while maintaining the scrap in solid state; and, f. repeatedly impacting said larger workpiece while hot in a harmonic press of the type having a pair of opposed platens and side restraints until the workpiece is converted to a substantially void-free body of steel and thereafter continuing to repeatedly impact the workpiece until it is reduced to a thickness of no more than 70 percent of its thickness at the time it became a solid piece of steel.
 41. The method of claim 40 wherein said bales are connected together by welding.
 42. The method of claim 41 wherein said bales during the baling operation are formed with reduced size projecting weldable end portions and the bales are welded together by welding one of said portions of one bale to another of said portions of another bale.
 43. The method of claim 40 wherein each of said bales is impacted to open its ends and said open ends are placed in juxtaposition and pressed together to connect said bales into said larger workpiece.
 44. The method of claim 40 wherein end portions of said bales are not compressed at the time the bale is formed and wherein each uncompressed end portion is placed in juxtaposition with an uncompressed end portion of another bale and the bales are pressed together to form said larger workpiece.
 45. The method of claim 40 wherein each of said bales is formed with end portions shaped for interlocking with another bale.
 46. The method of claim 40 wherein said bales are joined together by banding.
 47. The method of converting steel scrap to sheet steel while maintaining the steel in its solid state comprising the steps of: a. segregating steel scrap to provide a collection of scrap pieces having chemistry corresponding to the desired chemistry of the sheet to be formed; b. baling the segregated steel into a plurality of relatively small bales; c. transporting the small bales to a remote processing location; d. connecting the small bales to form a larger workpiece; e. cleaning the scrap prior to or subsequent to said baling step but prior to a subsequent impaction step; f. impacting the larger workpiece while cold to produce a compacted bale of generally rectangular cross section having a volume composed of from 30 to 90 percent by volume of steel; g. transporting the impacted workpiece to a two-zone oven; h. heating the workpiece to from 1,000*F. to 1,200*F. in the first zone; i. heating the workpiece to from 1,200*F. to 2,350*F. in said second zone in a reducing atmosphere while maintaining the workpiece in solid state; j. transporting the workpiece to a hot harmonic press while maintaining the workpiece in said reducing atmosphere and at an elevated temperature; k. impacting the workpiece in the hot harmonic press by constraining its sides while impacting its top and bottom surfaces with opposed platens; l. continuing to impact said workpiece with said hot harmonic press until it has been reduced to substantially void-free condition and thereafter reduced to no more than 70 percent of its thickness when it reached the substantially void-free condition thereby causing molecular flow of the molecules of said scrap under the conditions of confinement temperature and pressure to unite said scrap into a homogeneous slab of steel; and, m. finishing the slab into sheet steel.
 48. The method of claim 47 wherein the finishing of the slab into sheet steel includes tHe steps of transporting said slab while hot to a mill of the planetary type and rolling said slab in said planetary mill to produce steel strip having a thickness of not more than 1/20th the thickness of said bale.
 49. The method of claim 47 wherein the platens of said hot press are constrained for movement such that any point on each of the platens transcribes an initial forging path which is substantially reciprocal and transvrse to the path of workpiece travel and thereafter changing the constraint on said platens after a lead portion of said workpiece has been fed between the platens such that any point on one of said platens traverses another path having a workpiece feed motion paralleling the path of travel such that the press itself feeds the workpiece as it is forged into a slab.
 50. A method of converting pieces of scrap metal into a body of suitable metal useful in a manufacturing operation while maintaining the pieces in a solid state, comprising: a. selecting and segregating said pieces according to generally compatible chemistry classes; b. forming said pieces into a readily handable body having at least certain sides thereof in regular shape and having a density of at least 30 percent of solid; and c. feeding said body through an impaction station and simultaneously subjecting at least one planar cross section of said body to repeated impulsed impaction forces along said section while said body is in a heated solid state condition and while said section is perimetrically constrained, said impaction forces being sufficient to reduce said body to a void-free condition at the temperature level of said body.
 51. A method of making deep-drawing quality sheet steel from scrap metal, comprising: a. segregating and collecting steel scrap of substantially deep drawing quality; b. mechanically densifying said segregated scrap into a regular shaped body having a density at least 20 percent of solid but no greater than 55 percent of solid; c. subjecting said body to a cleaning function for removal of surface oils and oxide contaminates; d. subjecting at least one planar cross section of said body to repeated impulsed compacting forces along said section while said body is in a heated solid state condition within the range of 1,400*F to 2,000*F and while the cross section is perimetrically constrained, said compacting forces being sufficient to render said body free of voids while said body is within said temperature range; and, e. subjecting said void-free body to further compacting forces to produce sheet steel while in the heated condition above 1, 400*F.
 52. A method of making a composite structural quality steel from heterogeneous car body scrap, said car body scrap being derived from a reclamation process where lower melting non-ferrous elements are substantially removed, comprising: a. mixing ferrous powder of a desired ferrous chemistry with said car body scrap to attain a designated mixed steel composition of predetermined structural integrity; b. forming said mixture into a readily handable body having at least certain sides thereof in a regular shape, and having a density of at least 40 percent of solid but not greater than 55 percent of solid; and, c. subjecting at least one planar cross section of said body to repeated impulsed compacting forces along said section while said body is in a heated solid state condition and while said body section is perimetrally constrained, said compacting forces being sufficient to render said body free of voids at the temperature level of said body.
 53. A method of making steel continuously from scrap metal comprising: a. selecting and segregating scrap metal according to compatible chemistry classes and regulating the size of the scrap within each class; b. force feeding said scrap pieces into an extrusion die, said die having a throat greater in dimension that the maximum size of Scrap element being compressed therethrough, said scrap being compressed into an elongate continuous body a density of at least 30 percent of solid, said die being arranged to gradually converge said scrap elements into said body at said density; c. subjecting progressive planar cross sections of said body to repeated impulsed compacting forces along said section planes while said sections are perimetrically constrained, said compacting forces being sufficient to densify said elongated body to at least 75 percent of solid; and, d. heating said elongate body into the temperature range of at least 1,250*F to 2,000*F and while in said heated condition further subjecting said body to repeated impulsed compacting forces along planar cross sections thereof and also while perimetrally constrained at said sections to render said body free of voids at the temperature level thereof. 